Lateralization Of Emotion Research Articles

Affective self-report during the intracarotid sodium amobarbital test: Group differences

Emotional reactions are sometimes observed during the intracarotid sodium amobarbital test. For instance, euphoric/indifference reactions can be seen during right hemisphere inactivation and catastrophic reactions may accompany left hemisphere inactivation. Less dramatic changes can also be detected in affective self-report during left and right hemisphere amobarbital tests, with more negative affect reported during left hemisphere inactivation and either neutral or mildly positive affective states reported during right hemisphere inactivation. The current study not only replicated this effect, but in addition, found significant group differences. The first group (right way) showed a pattern of affective self-report during left and right amobarbital tests entirely consistent with prior findings, while a second group (wrong way) showed results that behaved in a diametrically opposite fashion. A third group (no change) showed little, if any, difference in affective self-report during left and right amobarbital tests. The major factor distinguishing the wrong way group from the other two appeared to be an asymmetrical distribution of left and right temporal lobe lesions in the former group. In contrast, the factor differentiating the right way group from the no change group appeared to be the relative degree of left hemisphere inactivation during the left hemisphere amobarbital test. The results are discussed not only in terms of their impact on theories of cerebral lateralization for emotion, but also in terms of methodological issues in this field.

681 Functional brain asymmetry in tuvinians. Relationships with alcohol consumption

This paper presents data suggesting a relationship between rat behavioral despair in the Porsolt test and motor lateralization in the T-maze test. In addition, experimental evidence suggests a functional coupling among dopaminergic systems, behavioral despair and motor lateralization. In the first experiment, female, not male, rats with a high level of behavioral despair showed a low level of behavioral lateralization. The inverse relationship was found in female offspring of mothers stressed during gestation. In comparison with unstressed-mother rats, the female offspring of stressed mothers showed an increase of dopamine (DA) and a decrease of dihydroxyphenylacetic acid (DOPAC) and Homovanillic (HVA) levels and of DOPAC:DA and HVA:DA indexes in the n. accumbens of the right side of the brain. No significant differences were found in the n. accumbens of the left brain. Taken together, the present data provide evidence of a relation between behavioral despair and motor lateralization, suggesting that the biological dopaminergic inervation of n. accumbens could be the basis for this functional coupling. Because the stress of gestant mothers modified these biochemical and behavioral variables, the present study also suggests that lateralization of behavior and emotion during adulthood can be modified by prenatal variables.

Footedness is a better predictor than is handedness of emotional lateralization

A tremendous amount of experimental work has attempted to identify reliable behavioural predictors of cerebral lateralization. Preferred handedness has been the most popular predictor, but some recent reports suggest that preferred footedness may serve as a more accurate predictor of functional laterality, especially in the left-handed population. The present study sought to test this claim by selectively recruiting individuals with either ‘crossed’ lateral preferences (right-handed and left-footed or left-handed and right-footed) or ‘uncrossed’ lateral preferences (right-handed and right-footed or left-handed and left-footed). Lateralization of emotional perception was assessed with two blocks of the dichotic Emotional Words Test (EWT), and lateral preference for both handedness and footedness was assessed using self-report questionnaires. Ear advantage on the dichotic task varied significantly with preferred foot ( P = 0.003), but not with preferred hand. Cerebral lateralization may be more related to footedness than to other lateral preferences.

Motor Lateralization, Behavioral Despair and Dopaminergic Brain Asymmetry After Prenatal Stress

This paper presents data suggesting a relationship between rat behavioral despair in the Porsolt test and motor lateralization in the T-maze test. In addition, experimental evidence suggests a functional coupling among dopaminergic systems, behavioral despair and motor lateralization. In the first experiment, female, not male, rats with a high level of behavioral despair showed a low level of behavioral lateralization. The inverse relationship was found in female offspring of mothers stressed during gestation. In comparison with unstressed-mother rats, the female offspring of stressed mothers showed an increase of dopamine (DA) and a decrease of dihydroxyphenylacetic acid (DOPAC) and Homovanillic (HVA) levels and of DOPAC:DA and HVA:DA indexes in the n. accumbens of the right side of the brain. No significant differences were found in the n. accumbens of the left brain. Taken together, the present data provide evidence of a relation between behavioral despair and motor lateralization, suggesting that the biological dopaminergic inervation of n. accumbens could be the basis for this functional coupling. Because the stress of gestant mothers modified these biochemical and behavioral variables, the present study also suggests that lateralization of behavior and emotion during adulthood can be modified by prenatal variables.

Affective neuroscience: the emergence of a discipline

This past year has seen significant advances in our understanding of the physiology of emotion. Attention continues to focus on the amygdala and its interconnections with prefrontal cortical regions. New evidence underscores the importance of lateralization for emotion. There are also new findings on the physiological predictors of individual differences in emotional behavior and experience, and on the role of autonomic arousal in emotional memory.

No Effects of Verbal Versus Imaginal Cognitive Strategies on Emotional Responses to Aversive Slides

A number of studies have indicated that the right hemisphere is specialized for (negative) emotions. Some authors have suggested that this specialization stems from the cognitive characteristics of this hemisphere. More specifically, the verbal and analytic approach that characterizes left hemisphere functioning would inhibit emotional reactions, whereas the imaginal and global approach that characterizes right hemisphere functioning would facilitate emotional reactivity. The present study examined whether these two cognitive strategies have, indeed, different effects on emotional responsivity. Subjects were exposed to a series of aversive slides. One group (n = 14) was instructed to process the slides in a verbal/analytic manner. The second group (n = 14) employed an imaginal/global strategy while viewing the slides. The third group (n = 14) was a control group that received no explicit instructions. Self-reported emotions, skin conductance responses, heart rate frequency, and eye blink startles were recorded. There were no differences between the three groups with regard to any of these variables. Thus, no evidence was obtained to support the idea that processing modes (i.e., verbal/analytic versus imaginal/global) have a differential impact on emotional reactivity. The implications for theories about lateralization of emotions and for cognitive therapy are discussed.

The Consequences of Experimentally Induced and Chronic Unilateral Pain: Reflections of Hemispheric Lateralization of Emotion

In a series of three studies with right handed subjects, left side pain is tolerated less well than right side pain with a cold pressor, and results in greater emotional disturbance, both with a cold pressor and in chronic pain patients. In the second study where comparisons are made with non-stimulated controls, acute left side pain results in higher state anxiety scores than controls; right side pain and control groups are comparable. The differences between the reactions to left and right side pain are consistent with activation of the emotional properties of the hemisphere contralateral to the painful stimulation.

Hemispheric asymmetries in adults' perception of infant emotional expressions.

Accounts of emotion lateralization propose either overall right hemisphere (RH) advantage or differential RH versus left hemisphere (LH) involvement depending on the negative-positive valence of emotions. Perceptual studies generally show RH specialization. Yet viewer emotional responses may enhance valence effects. Because infant faces elicit heightened emotion in viewers, perceptual asymmetries with chimeric infant faces were assessed. First, it was determined that chimeras must be paired with their counterparts, not their mirror images, to tap viewers' sensitivity to adult facial asymmetries. Results showed an RH perceptual bias for infant cries but bihemispheric sensitivity to asymmetries in infant smiles. This effect was not due to LH featural versus RH holistic processing and held for additional, intensity-matched, spontaneous expressions. Specialized RH sensitivity to infant cries may reflect an evolutionary advantage for rapid response to infant distress.

Crying seizures

We report seven patients with crying during video-EEG-documented simple or complex partial seizures. During simple partial seizures, crying occurred with or without appropriate affect. Crying occurred postictally in two patients and was associated with persistent spiking in one of them. Six patients had ictal activity in the nondominant hemisphere, maximal in the anteromesial temporal region in five and in the mesial frontal region in another. These cases support theories proposing a lateralization of emotion, with right hemisphere dominance for negative affective states.

Shared neuroendocrine patterns of post-traumatic stress disorder and alexithymia.

High norepinephrine/cortisol ratios have been shown to be useful indicators of post-traumatic stress disorder (PTSD). Alexithymia can result from overwhelming stress; thus, we hypothesized that sympathetic-adrenal medullary/hypothalamic-pituitary adrenal ratios would be positively associated with alexithymia severity. In the present study, we correlated 3-methoxy-4-hydroxyphenylethylene glycol (MHPG)/adrenocorticotropic hormone (ACTH) and MHPG/cortisol ratios with self-report Toronto Alexithymia Scale (TAS) scores in a group (n = 17) of nondepressed, formerly alcohol-dependent men. The correlations between the respective ratios and TAS scores were 0.515 (p = 0.034) and 0.561 (p = 0.019). We suggest that increasing degrees of alexithymia are accompanied by an increasing separation of these two endocrine systems and then speculate that this dissociation has an anatomical basis in the lateralization of emotions.

Hemifacial display of emotion in the resting state.

The human face at rest displays distinguishable asymmetries with some lateralization of emotion or expression. The asymmetrical nature of the resting face was examined by preparing hemifacial composites, left-left, right-right, along with normal facial orientation. The left side and right side composites were constructed by using the lateral half of one side of the face and its mirror-reversal. The left side facial composites were found to be more emotional than the right side or normal facial orientations of neutral expressions.

Hemifacial Display of Emotion in the Resting State

The human face at rest displays distinguishable asymmetries with some lateralization of emotion or expression. The asymmetrical nature of the resting face was examined by preparing hemifacial composites, left–left, right–right, along with normal facial orientation. The left side and right side composites were constructed by using the lateral half of one side of the face and its mirror-reversal. The left side facial composites were found to be more emotional than the right side or normal facial orientations of neutral expressions.

Lateralization for the expression and perception of facial emotion as a function of age

In order to test the hypothesis of right hemisphere changes with age, this study examined lateralization for facial emotion in young, middle-aged, and older women ( N=90). For expression, subjects were photographed while posing positive and negative emotions. Composite photographs were created and rated for intensity. For perception, subjects were required to make intensity judgements about emotional chimeric faces. Overall, subjects demonstrated significant left-sided facial asymmetry for expression and significant left hemispace biases for perception. The findings for facial expression were not influenced by emotional valence or resting face asymmetries. There were no changes in lateralization as a function of age for either expression or perception. Taken together, these findings lend support to the notion that the right hemisphere mediates emotional processing across the adult life span.

Pharmacological effects on lateralized behavior

Sixteen student volunteers were administered a placebo and 50 mg. of chlorpromazine in tablet form, on separate occasions, two hours before testing. The three tests measured dichotic listening performance, lateral eye movements while answering questions about spatial location and verbal meaning, and lateralized facial expression while relating pleasant and unpleasant life incidents. Results showed that chlorpromazine increased the number of trials showing an ear advantage in dichotic listening. Chlorpromazine reduced lateral and increased vertical eye movements in response to the questions about spatial location and verbal meaning. Under the placebo both negative and positive emotions were expressed more in the left face. Although chlorpromazine did not affect this lateralization of negative emotions, the expression of positive emotions occurred equally often on the two sides of the face under chlorpromazine. Results may be related to an effect of chlorpromazine on the asymmetrical dopamine pathways of the brain. It is suggested that the findings may be related to a left hemisphere deficit in schizophrenia.

Effects of mood on lacrimal flow: sex differences and asymmetry.

ABSTRACTAfter baseline assessments or mood and lacrimal flow in each eye, 80 subjects participated in either a sadness or happiness mood manipulation. They were requested to generate imagery of sad or happy events in their lives and (o reexperience the associated affect. Self‐reports of mood and lacrimal flow were then reassessed. For both sexes, the sadness condition was associated with reports of greater dysphoric affect than the elation condition. In females, lacrimal flow tended to increase following the sadness manipulation and significantly decreased following the happiness manipulation. Mood did not significantly influence flow values in males. Among females, the left eye showed larger changes than the right as a function of mood condition. The nature of the sex differences, the implications of the findings for theories of lateralization of emotion, and the utility of the lacrimal flow measure as an index of mood are discussed.

Hemispheric lateralization of emotions: Absence of electrophysiological arguments

EEG lateralization was examined during happy and sad emotional expression in 24 subjects. Happy and sad emotional states were induced by asking subjects to mentally review previously shown film-sequences. Our results failed to replicate those of previous studies, in that they showed no frontal alpha lateralization as a function of emotion. The authors discuss the literature and suggest caution before asserting the existence of electrophysiological arguments in favor of lateralization of emotions in humans.

Hemispheric lateralization of functions related to emotion

We have reviewed the evidence that processes and functions related to perception and expression of emotions are represented asymmetrically in the cerebral hemispheres. The literature describes three possible aspects of emotional lateralization: that emotions are better recognized by the right hemisphere; that control of emotional expression and related behaviors takes place principally in the right hemisphere; and that the right hemisphere is specialized for dealing with negative emotions, while the left is specialized for dealing with positive emotions. Evidence for the three hypotheses derives from methodologically diverse studies in unimpaired, brain-lesioned, and mood-disordered populations. Relatively little of the work has been precisely replicated, and conclusions rest on parallel lines of evidence from diverse sources. The present level of knowledge suggests a model of emotional control based on interactive inhibition between a right negatively biased and left positively biased hemisphere. However, the details of such a model, including the precise conditions under which emotion-related functions are lateralized, and the mechanisms of such lateralization have yet to be elucidated.

Differential hemispheric lateralization for positive and negative emotion: An electromyographic study

Differential hemispheric lateralization for positive and negative emotion: An electromyographic study

Differential lateralization for positive and negative emotion in the human brain: EEG spectral analysis

The present experiment utilized EEG spectral analysis to investigate lateralization for emotional processes in the human brain. In frontal zones, a differential lateralization for positive and negative emotion was observed, with relative left-hemispheric activation (as measured by decreases in alpha abundance) for positive emotions and relative right-hemispheric activation for negative emotions. In parietal zones, a differential lateralization for verbal and spatial processes was observed, with relative left-hemispheric activation for verbal questions and relative right-hemispheric activation for spatial questions. Examination of EEG bands other than alpha (i.e. delta, theta, beta, and total power) suggested that emotional and cognitive processes are further distinguished by different EEG spectral patterns.

The Psychobiology of Affective Development

Preface 1. Ann E. Kelley and Louis Stinus Neuroanatomical and Neurochemical Substrates of Affective Behavior 2. Victor H. Denenberg, Michael J. Hofmann, Glenn D. Rosen and David A. Yutzey Cerebral Asymmetry and Behavioral Laterality: Some Psychobiological Considerations 3. Stephen J. Suomi The Development of Affect in Rhesus Monkeys 4. Carol Zander Malatesta and Carroll E. Izard The Ontogenesis of Human Social Signals: From Biological Imperative to Symbol Utilization 5. Theodore J. Gaensbauer and Susan Hiatt Facial Communication of Emotion in Early Infancy 6. Barry M. Lester Infant Crying and the Development of Communication 7. Marcel Kinsbourne and Brenda Bemporad Lateralization of Emotion: A Model and the Evidence 8. Joan C. Borod and Elissa Koff Asymmetries in Affective Facial Expression: Behavior and Anatomy 9. Sara L. Weber and Harold A. Sackeim The Development of Functional Brain Asymmetry in the Regulation of Emotion 10. Nathan A. Fox and Richard J. Davidson Hemispheric Substrates of Affect: A Developmental Model. Author Index. Subject Index.